This small business innovation research Phase I project is concerned with the design and development of a new, direct method for determination of ozone contact time in disinfection processes. A color test strip will be used to monitor the contact time (product of ozone concentration and disinfection time), giving a simple, real-time, and broad range measurement of the degree of disinfection. The method involves impregnation of an ozone-reactive dye in an ozone-stable polymeric substrate that can be introduced into a disinfection environment where it will be slowly bleached. The proposed Phase I effort will be utilized to design a cost-effective method for determination of contact time in ozone disinfection processes. The benefits of this color strip are: (i) real-time measurement of ozone contact time, (ii) simple determination by color change, and (iii) broad working range. Briefly, in Phase I research will be carried out to investigate critical issues of ozone bleaching of dyes incorporated in a polymeric substrate and to relate the degree of bleaching to ozone contact time. PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE